Line length effect

Figure 24.15 The line length effect even when the sending-end and receiving-end voltages and currents are maintained at unity p.f.

Line length effect or Ferranti effect, sin 6, that will determine the optimum line length which will also depend upon whether it is a radial or a symmetrical line. 

Ey = phase voltage at the transmiliing-end Vy = phase voltage at the receiving-end By = line length effect or Ferranti effect at the end of the line, in degrees /i = load current P-JQ Vj... 

This product can be reduced by reducing X, using series capacitance with a reactance X, which will reduce to - Xq. This is where reactive control plays a major role. By meticulous reactive power manage-ment, the Ferranti effect can be controlled and the electrical line length increased to the desired level. It is a different matter that the electrieal length of the line cannot be raised infinitely, for reasons of stability, as discussed later. 

Table 24.4 Far-end voltage, due to the Ferranti effect, in a 400 kV TZ type line, at different line lengths...

The rest of the procedure, even the inferences drawn above, would remain the same as for a radial line. The only differenee now is that the system would beeome suitable for twiee the lengths of the radial lines as a result of the midpoint effect which doubles the line length. 

Derive an equation similar to Eq. 9.4 for the effective bulk self-diffusivity, ( D), in the presence of fast dislocation diffusion. Assume that the dislocations are present at a density, p, corresponding to the dislocation line length in a unit volume of material. 

Transmission Line Structures and Characteristics. When interconnections exceed the critical line length, transmission lines with proper terminations are used to effectively couple the signal into the line, to minimize reflections along the line and from its ends, and to minimize crosstalk with adjacent lines. Transmission line structures provide a controlled environment... 

Figure 3.29 Linear moduli G and G" versus frequency shifted via time-temperature superposition to 27°C for a polybutadiene melt of molecular weight 360,000 and of low polydispersity. The dashed line is the prediction of reptation theory given by Eq. (3-67) the solid line includes effects of fluctuations in the length of the primitive path. (From Pearson 1987.)...

The chain length effect is very pronounced in the data shown in Fig. 33 for v, excitation. In aniline there is no IVR. In methylaniline, there are recurrences, but weak in modulation. In the ethyl species, there is the hint of the biexponential behavior that is fully present in the propyl decay. In butylani-line, the fast component dominates. Clearly, as the chain length increases, the dynamics of IVR changes. 

To analyze the effect of number of branches, we consider the configuration shown in Fig. 10. The line length Transmitter- Receiver (Tx-Rx) was kept constant at 60 m i.e. k = h- h= h = 15 m, with one, two and three disturbed branches. All branches were 5 m long (dii = d.21 = dsi = 5m) and load Zbru, Zb 21 and Zbrsi were terminated in open circuit, while Zdcii/ Zdcii and Zdc3i are the line characteristic impedances. We repeat the same test as before simulating the transfer function with respect the number of branches. 

Once the size and shape of the board is decided on, any areas on the board that cannot be used for parts are defined using fill areas that prevent parts placement within their perimeter. The proper parts placement should result in a cost-effective design and meet manufacturing standards. Critical lines may not allow vias in which case they must be routed only on the surface. Feedback loops must be kept short and equal line length requirements and shielding requirements, if any, should be met. Layout could be on a grid with components oriented in one direction to increase assembly speed, eliminate errors, and improve inspection. Devices should be placed parallel to the edges of the board (ASM, 1989 Byers, 1991). 

Figure 13.110 shows a line-segmented or line-insertion combiner, where the various transmitter inputs are introduced sequentially. The fine lengths between the cavities and the tee junctions are critical, each about 1/2-wavelength long, adjusted for effects of cavity loop effective length, effective length of the tee connections, and velocity factor of the cable type employed. 

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